显示本周周次 显示本周起始及终止日期

 显示本周周次：

//   <summary>  

    ///   返回一个数组长度为3的字符串数组  
    ///   </summary>  
    ///   <returns>GetWeekDay[0]=周次;GetWeekDay[1]=该周第一天;GetWeekDay[2]=该周最后一天</returns>  
    public string[] GetWeekDay()
    {
        string[] inti = new string[3];
        DateTime day = DateTime.Parse(DateTime.Today.Year + "-1-1");
        System.DayOfWeek dateTime = day.DayOfWeek;
        int DayCount = DateTime.Today.DayOfYear;
        int i = (DayCount + aa(dateTime) - 2) / 7 + 1;
        inti[0] = i.ToString();

        inti[1] = day.AddDays(DayCount - 1).ToString("yyyy年MM月dd日");
        inti[2] = day.AddDays(DayCount + 5).ToString("yyyy年MM月dd日");
        Response.Write("第"+i+"周");
     
        return inti;
    }

    private int aa(System.DayOfWeek weekday)
    {
        switch (weekday.ToString())
        {
            case "Sunday":
                return 1;
            case "Monday":
                return 2;
            case "Tuesday":
                return 3;
            case "Wednesday":
                return 4;
            case "Thursday":
                return 5;
            case "Friday":
                return 6;
            case "Saturday":
                return 0;
            default:
                return 8;
        }

    }

 //////////////////////////////////////////////////////////////////
 C#显示本周日期收藏
/// <summary>
/// 计算本周起始日期（礼拜一的日期）
/// </summary>
/// <param name="someDate">该周中任意一天</param>
/// <returns>返回礼拜一日期，后面的具体时、分、秒和传入值相等</returns>
public static DateTime CalculateFirstDateOfWeek(DateTime someDate)
{
    int i = someDate.DayOfWeek - DayOfWeek.Monday;
    if (i == -1) i = 6;// i值 > = 0 ，因为枚举原因，Sunday排在最前，此时Sunday-Monday=-1，必须+7=6。
    TimeSpan ts = new TimeSpan(i, 0, 0, 0);
    return someDate.Subtract(ts);
}

/// <summary>
/// 计算本周结束日期（礼拜日的日期）
/// </summary>
/// <param name="someDate">该周中任意一天</param>
/// <returns>返回礼拜日日期，后面的具体时、分、秒和传入值相等</returns>
public static DateTime CalculateLastDateOfWeek(DateTime someDate)
{
    int i = someDate.DayOfWeek - DayOfWeek.Sunday;
    if(i != 0) i = 7 - i;// 因为枚举原因，Sunday排在最前，相减间隔要被7减。
    TimeSpan ts = new TimeSpan(i, 0, 0, 0);
    return someDate.Add(ts);
}

/// <summary>
/// 判断选择的日期是否是本周（根据系统当前时间决定的‘本周’比较而言）
/// </summary>
/// <param name="someDate"></param>
/// <returns></returns>
public static bool IsThisWeek(DateTime someDate)
{
    //得到someDate对应的周一
    DateTime someMon = CalculateFirstDateOfWeek(someDate);
    //得到本周一
    DateTime nowMon = CalculateFirstDateOfWeek(DateTime.Now);

    TimeSpan ts = someMon - nowMon;
    if (ts.Days < 0)
        ts = -ts;//取正
    if (ts.Days >= 7)
    {
        return false;
    }
    else
    {
        return true;
    }
}

从当前日期得到本周的开始和结束日期, 本周、本月、本年起止时间  

2011-01-05 11:58:15|  分类： sql |  标签：datetime  string  yyyy  tostring  convert   |字号大中小 订阅

 

 

  /// <summary>
        /// 本周起止时间
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        private string weekrange(System.DateTime dt)
        {
            int weeknow = Convert.ToInt32(dt.DayOfWeek);          
            int daydiff = (-1) * weeknow+1;
            int dayadd = 7 - weeknow;
            string datebegin = System.DateTime.Now.AddDays(daydiff).ToString("yyyy-MM-dd");
            string dateend = System.DateTime.Now.AddDays(dayadd).ToString("yyyy-MM-dd");
            return datebegin + " / " +dateend;
        }

      // 本月起止时间
        private string months()
        {
            string moth = Convert.ToDateTime(DateTime.Now).ToString("yyyy-MM-")+"01";
            string mothDay =Convert .ToDateTime (DateTime.Now).ToString("yyyy-MM-dd");
            return moth + "/" + mothDay;
        }

     // 本年起止时间
        private string years()
        {
            string year = Convert.ToDateTime(DateTime.Now).ToString("yyyy") + "-01-01";
            string yearDay = Convert.ToDateTime(DateTime.Now).ToString("yyyy-MM-dd");
            return year + "/" + yearDay;
        }